Kroon Hall, Yale School of Forestry and Environmental Studies

Challenge

Yale required a significant building program for a small urban site and maintains LEED goals for all new campus buildings. The City of New Haven required that all stormwater be treated and mitigated on-site prior to discharge to the City system. Site slopes and the underground building service node limited the potential for infiltration with less than 1 ft of soil depth available on top of the structure.

Solution

The green roof built atop the loading docks and utilities incorporates a water feature that is both social amneity and a key part of a rainwater harvesting system. Stormwater is collected, treated, stored and recycled through an interactive pond that uses water-based phytoremediation. Water is used for landscape irrigation or sent to a tank for further treatment for use in the building.

• The site design locates the building and services to create 2 new plazas and 2 new courtyards. The south courtyard is formed by a 19,000 sf ground-level green roof.
• The service node beneath the south courtyard centralizes and uses a single driveway for all trash, recycling and delivery traffic for the southwest corner of Science Hill.
• The first (and dirtiest) inch of stormwater from Kroon’s roof and northern part of the site is collected and channeled to the 16,000-sf phytoremediation pond, where native wetland plants remove nitogren, phosphates and particulates.
• A 20,000-gallon underground harvesting tank collects and stores pond overflow and additional rainwater, which is recirculated, used for irrigation, or diverted to a 940-gallon “day” tank where it is filtered and disinfected for use in toilets.
• Water from building foundation pumps provides supplemental water for the greywater resuse system, improving reliability by 50%. This water would otherwise be discharged to the combined sewer system.
• The landscape uses 25 varieties of plants native to Connecticut.
• Kroon Hall also features solar panels, geothermal wells, and daylight harvesting.

• Rainwater harvest systems may need to be supplemented to meet demand for greywater reuse. In this case, water discharged from building foundation pumps provides a make-up source.
• A “first-flush” device is needed to remove trash, sediment, and other settleable solids from stormwater runoff.
• Mats of trailing plant roots in a pond can be more effective than soil for cleaning runoff water.

Project Team

Design Architect: Hopkins Architects
Executive Architect: Centerbrook Architects & Planners, LLP
Sustainable Design: Atelier Ten
Landscape Architect: OLIN
Civil Engineer and Storm Water Management: Nitsch Engineering, Inc.
Geothermal Engineers: Haley and Aldrich
Structural, MEP, Fire Protection Engineers: ARUP
Facade Engineering/Thermal Performance: Simpson Gumpertz & Heger, Inc.
Architectural Lighting and Acoustical Design: ARUP, Specialty Consultants
Materials Handling: SEA Consultants, Inc.
Code Consultant: P.R Sherman, Inc.
Specification Consultant: Kalin Associates
Cost Estimator: Faithful + Gould
Construction Manager: Turner Construction Company

Role of the Landscape Architect

Led the design of an innovative, didactic and social landscape over structure.